Antistatic lubricating composition for textile fibers



United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE An antistatic composition for textile fibers containing a diethanol amine salt of a phosphate ester and a condensate of ethylene oxide and nonlyphenol prevents static charge accumulation on fiber surface and does not adversely affect the production of high quality yarns.

This application is a continuation-in-part of Ser. No. 450,505, filed Apr. 23, 1965, now abandoned. This invention relates to textile filamentary materials having improved qualities and, more particularly, concerns acrylic filamentary material bearing an antistatic lubricating composition.

In the conversion of synthetic fibers to yarn, the fibers are repeatedly subjected to sliding contact with adjacent fibers and the equipment used to process them. As is well-known, this sliding contact results in the generation of a static charge which can interfere with successful utilization of the fibers. Antistatic agents can be employed to prevent the accumulation of a high level of static charge but such agents must not interfere with the production of high quality yarns, for example, by adversely affecting the frictional characteristics of the fibers.

It is the object of this invention to provide a lubricating composition for synthetic fibers which acts to decrease the tendency of a static charge to accumulate on the fiber surface. Another object of the invention is to provide synthetic fibers such as acrylic fibers bearing the antistatic lubricating composition and a method of providing those coated fibers.

These and other objects are accomplished in the present invention in acrylic fibers having on the surfaces of the fibers a composition the active components of which consist, by weight, of to parts of a diethanolamine salt of a phosphate ester selected from the group consisting of (A) mixtures of orthophosphate esters of the general formula 0 )x )3-x wherein R represents a straight-chained, saturated, primary aliphatic hydrocarbon radical of 8 to 18 C-atoms and x is an integer not greater than 2, and (B) mixtures of higher phosphate esters of the general formula wherein n is an integer from 1 to 6 and R is selected from the group consisting of hydrogen atoms and straight-chained, saturated primary aliphatic hydrocarbon radical of 8 to 18 C-atoms and wherein on the average one-half of the Rs in the mixture are hydrogen atoms, and 75 to 80 parts of a condensate of ethylene oxide and 3,428,481 Patented Feb. 18, 1969 nonylphenol containing between 8 and 12 mols of ethylene oxide per mol of nonylphenol. The stated composition provides good lubricating and antistatic properties to the resulting coated fibers without adverse effect on other desired properties.

The salts of the orthophosphate esters can be prepared as shown in US. Patent No. 2,676,122, issued to Me- Carthy Apr. 20, 1954. In preparing compounds of this type, aliphatic alcohols are reacted with phosphorus pentoxide to give a mixture of the monoand diesters which is then neutralized with an alkanolamine, preferably diethanolamine, to form the corresponding salts. The aliphatic alcohols are straight-chain saturated primary monohydric alcohols having between 8 and 16 carbon atoms. Preferably, the mixture of alcohols will be one in which n-octanol is the major constituent. Particularly good results are obtained when a mixture of salts having about 1.1 to about 1.6 alkyl group per phosphorus atom is used.

The higher phosphates such as the pyrophosphates, triphosphates, tetraphosphates and the like are characterized as having POP linkages. The diethanolamine salts of the esters of the higher phosphates are prepared as disclosed in US. Patent No. 2,742,379, issued to Schofield Apr. 17, 1956. The aliphatic alcohols described above are reacted with phosphorus pentoxide in a ratio of 2 mols of alcohol to 1 mol of the pentoxide. In the compositions obtained, about to 100 weight percent of the phosphorus is connected by linkage through an oxygen atom to another phosphorus atom. Preferably, these esters are prepared from a mixture of alcohols in which n-dodecanol is the major constituent.

The diethanolamine salts of the orthophosphates and higher phosphates described above may be employed alone or in admixture in the practice of this invention. A preferred composition contains both the orthophosphates and the higher phosphates in a weight ratio of about 1 to 1. The phosphates are used in this invention in an amount of 20 to 25 parts with 75 to parts of the phenol-ethylene oxide condensate. If amounts beyond that limit are used, the viscosity of the composition is excessive and the resulting highly viscous coating on the fibers impairs fiber movement and interferes with the production of high quality yarn; with lower phosphate contents, the static protection becomes inadequate.

The other active constituent of the compositions applied to fibers in accordance with this invention is the material obtained by condensing 1 mol of nonylphenol with between about 8 to 12 mols of ethylene oxide. It is believed that such a condensate provides surfactant and lubricating properties to the composition. When about 3 to 4 parts of one of these condensation materials is combined with one part of the phosphate, there is obtained a composition with a low viscosity that can be readily added to water to form highly stable emulsions. It is preferred to apply the composition to fibers from an aqueous emulsion since this is convenient for uniformly applying small amounts, e.g., less than 1% by Weight, to the fibers. Upon evaporation of water, there remains on the surface of the fibers a uniform coating of antistatic lubricant. This composition shows practically no change of antistatic properties on aging and can be used over a wide range of relative humidities. In addition, the composition of this invention can be heated without deleterious effects and does not result in the undesirable formation of condensed volatiles as can occur in the cooler sections of heating ovens.

As indicated, the antistatic lubricating composition is preferably applied to the filamentary material in the form of an aqueous emulsion. Stable emulsions of the composition can be prepared ranging in concentration from 1% up to about 85%, by weight, and emulsions containing about 20 to 35% by weight of the compositions will normally be used for roll application. Application also can be by spraying using, for example, an emulsion having a concentration of 80 to 85% or by dipping in a bath of a 1 to 5% emulsion. By whatever method, the amount of the composition applied to the yarn will be about 0.1% to about 1.0%, and preferably from about 0.2% to about 0.5%, by weight, measured on a water-free basis and based on the total weight of the yarn. Preferably, the composition will be applied to tows of continuous filaments.

The antistatic lubricating composition of this invention is particularly useful on acrylic filamentary materials. By acrylic fibers is meant those fibers prepared from polyacrylonitrile, and copolymers of acrylonitrile and other monoethylenically unsaturated monomers copolymerizable therewith which contain at least 85 percent polymerized acrylonitrile and up to 15 percent of the copolymerizable monomers. Preparation of these polymers is well known, such processes being disclosed in U.S. Patents 2,486,241; 2,546,238; 2,837,500; and 2,837,501 as well as others.

The effectiveness of the composition in preventing the accumulation of a high static level is determined by measuring the current which flows along a section of the fiber under an applied voltage. The measurement is made by determination of log R values as follows:

The [finish emulsion is uniformly applied by a precision metering device to a 75-denier 30-filament acrylic yarn as the yarn is being wound on a package. The packaged yarn is then held at room temperature for at least 24 hours. After this conditioning the yarn is transferred to a sample holder which consists of two stainless-steel tubes. The tubes are 3 inches (7.62 cms.) long, with an outside diameter of 1.25 inches (3.18 cms.) and have a wall thickness of 0.049 inch (0.125 cm.). The tubes are held parallel and 0.75 inch (1.91 cms.) apart by two spacers of polytetrafluoroethylene forced over their ends. One of the spacers contains two banana plug receptacles, which make electrical contact with the tubes. Fifty turns of the yarn are wound, side-by-side, onto the holder using just enough tension to prevent sloughing. The loose ends are fastened with adhesive tape. After the yarn is wound onto the holder, it is exposed, at 20 C., to a controlled relative humidity for 24 hours. The relative humidity is variable and measurements are made at various levels of relative humidity at 20 C. Following this exposure, current flow is measured using a Beckrnan Micromicroammeter which provides a well-regulated direct current potential of 210 volts and indicates current in the range from to 3 X 10- amperes. The electrodes of the ammeter are a pair of banana plugs for insertion into the receptacles of the sample holder. The resistance and log R are then calculated.

The following example is given to illustrate the invention further; unless otherwise stated, all parts are by weight.

EXAMPLE I Twenty parts of a diethanol amine salt of an alkyl orthophosphate is added to 80 parts of the material obtained by condensing 1 mol of nonylphenol with 10.5 mols of ethylene oxide to give a composition having a viscosity of about 400 centipoises at 25 C. The alkyl phosphate is a partial ester of a mixture consisting of 27.0 parts of n-octanol, 15.9 parts of n-decanol and 10.7 parts of a commercial grade of lauryl alcohol which contains small amounts of the corresponding 10-, 14-, and 16-carbon alcohols. The partial ester, which contains both the monoand dialkyl esters, is then neutralized with diethanolamine. Thirty parts of this composition is added, with stirring, to 70 parts of water to give a stable finish emulsion. The finish emulsion is then applied to acrylic fibers so as to deposit thereon about 0.3%, by weight of the composition, based on the weight of the treated fibers. Three samples of these treated fibers are separately conditioned at 32%, 65% and 78% relative humidity and the log R values determined as previously described. The log R values are found to be,

respectively, 10.3, 9.2 and 8.5. The fibers are easily proc- EXAMPLE II A mixture of 0.566 mol of n-octanol, 0.286 mol of ndecanol and 0.148 mol of a commercial grade lauryl alcohol is reacted With 0.318 mol of phosphorus pentoxide and 0.816 mol of diethanolamine added; the procedure and conditions being those described in Example I of U.S. Patent 2,676,122. Ten parts of this salt is then combined with 10 parts of the salt obtained by the teaching of Example I of U.S. Patent 2,742,379 and the combined materials added to 80 parts of the ethylene oxide condensate of Example I. Thirty parts of this composition is added, wtih stirring, to 70 parts of water to give a stable finish emulsion. A tow of acrylic fibers is passed through a bath of the finish so as to provide on the fibers about 0.3 percent, by weight, of the composition. Staple fibers from this tow are readily converted to high quality yarns.

The antistatic lubricant composition of this invention is of primary use as a pre-crimp finish on acrylic lfibers. However, it may be employed on acrylic fibers at other stages of processing where its properties are of particular need to facilitate production.

It will be appreciated that changes can be made from the detailed disclosure of the invention without departing from its scope.

What is claimed is:

1. Acrylic fibers from textile applications having on their surfaces a composition that consists, by weight, of 20 to 25 parts of a diethanolamine salt of a phosphate ester selected from the group consisting of:

(A) orthophosphate esters having the formula 0 T )r- )a-; wherein R is a straight-chained, saturated, primary aliphatic hydrocarbon radical of 8 to 18 carbon atoms and x is an integer not greater than 2, and (B) higher phosphate esters having the formula wherein R is a hydrogen atom or a straight-chained saturated primary aliphatic hydrocarbon radical of 8 to 18 carbon atoms, and n is an integer from 1 to 6; and 75 to 80 parts of a condensate of nonylphenol and ethylene oxide in a ratio of between 8 to 12 mols of ethylene oxide per mol of nonylphenol.

2. Acrylic fibers in accordance with claim 1 containing said composition in an amount, based on the weight of the fibers, of about 0.1 to about 1.0%.

3. Acrylic fibers containing about 0.2 to about 0.5 based on the fibers, of a composition that consists, by weight, of 20 parts of the diethanolamine salt of a phosphate ester in which the alkyl radicals contain 8 to 18 carbon atoms, and 80 parts of a condensate of nonylphenol and ethylene oxide in which there are between 8 and 12 mols of ethylene oxide per mol of nonylphenol.

(References on following page) 5 6 References Cited 3,170,877 2/ 1965 Beiswanger et a1 252-8.8

UNITED STATES PATENTS 3,333,983 8/1967 SeI'Iet et a1 117-138.8 X 10/1942 Dickey et a1. 252-8.8 655 517 EZ :ATENTS 4/1954 McCarthy 117-139.s 5 3 3 Cam 4/1954 Fortess et 117-1395 X WILLIAM D. MARTIN, Primary Examiner.

7/1958 Haas a1 2528'9 X I. E. MILLER, 111., Assistant Examiner.

9/1958 Fortess et a1. 117139.5 X

3/1961 Macura et a1. 252-88 x 10 10/1962 Copes et a1. 252-8.8 117139-5 

